Quantum
annealing is an optimization method designed to take advantage of
quantum phenomena, such as quantum superposition, tunneling and
quantum fluctuations. Diabatic transactions between energy levels,
and thermal excitations and relaxation, can play an important role in
quantum annealing (as opposed to adiabatic quantum computation).
DWave

has
implemented a physical quantum annealing prototype with up to 512
qubits. The decoherence time scale in this device is much shorter
than the annealing time. I will review recent work done in this
prototype. On the one hand, we find evidence of entanglement within
eight superconducting flux qubits. On the other hand, we find no
evidence of a quantum speedup for the case of random Ising glasses
when the entire data set is considered, and obtain inconclusive
results when comparing subsets of problems on an instance-by-instance
basis. I will present preliminary new results and theory comparing
noisy quantum annealing, the DWave prototype, and several numerical
models.